Pin tumbler lock



Patented June 26, 1945 UNITED STATES PATENT Aoi-F,lice,A`-4

Fritz Schori', Wetzikon, Switzerland, assigner to- Bauer A. G., Zurich, Switzerland Application. February 4, 1943, serial No. 474,724

In Switzerland Decemberl, 1941 This. invention relates to a pin-tumbler lock having a cylinder, which is rotatably mounted in the lock housing, and tumblers that are displaceable transversely of the cylinder and are so adjustable by means of a control key that the cylinder is unlocked, that is, released for being rotated.

It is known to use an. arrangement including pin-tumblers which are loaded by compression springs, alternatively, in combination with balls., and which, incooperating-With a system of teeth or recesses arrangedA on the key shank, are displaced or adjusted as required against said spring influence for unlocking the rotatablel cylinder. Thev functioning of these pin-tumblers can be checkedv or frustrated altogether, for example, by dust having accumulated in the lock, particularly if the dust forms4 a hard' crust by'intermixing With oil or moisture, or if by action of ifrost ice is for-med. In such events it may happen that resistances arising in such manner can be overcome by the springs associated with the pin-tumblers only with diiculty or not at al1.

The pin-tumblers must then be caused to func- 4 inserting the key into the said plug the slide is positively -displaced by cooperation of the key With one of the pn-tumblers and that by action of the slide the other pin-tumblers are adjusted into their unlocked positions, while in retracting the key, by cooperation of the latter with the system of pin-tumblers, the slide is positively restored and by slide action the pin-tumbler which displaced the slide is also restored so as to be moved into locking position.

By this means the proper functioning of the pin-tumblers is ensured.

In the accompanying drawing an embodiment of the invention is illustrated by way of example, inwhich Fig. 1 depicts an axial section of the lock, according to the invention, the pin-tumblers being shown in locking position;

Fig. 2 is a cross section on the line II-II in Iigz 1, and

Fis, 3 shows an axial section of the lock with pin-tumblers moved out offloeking position.

The numeral i designatesthe cylindrical lock casing having a cylinder 2 and a plug 3. Whichis rotatably mounted in a stepped olbore.v Inrivc radial bores of theV plug 3` distributed axially. over the latter pin-tumblers 4 are displaceably guided and have correlated thereto,jin known manner, studs 5 for the reception o f whicnthecylinder 2 is` provided withv correspondingbores. The two sections 4, 5 ofthe pin-tumblers are formed with points at their opposite ends. in aknownmanner. The keyhole. for the; insertion of the flat control key Tis. denoted by. 6. ADependingon the number of pin-tumblers 4, on one vof the dat sides ci said key ve depressed rests or engaging .portions 8.0i relatively varied shapejare provided. Theseengaging, portions are'v distributed in accordance with the permutation chosen, tour,v of said engaging portions are formed by recesses, whereas thefth is formed by a front oblique face. on the key shank. To these engaging p0rtions .8 of the key Vshank the sections, 4 of the pin-tumblers 4, 5. are tted, the sections 5 thereof .being coordinated with depressed.y engaging poi-tionsa of the slide I0 which latter vportions arl-distributed in accordance with the permutation chosen. The slide l0 is guidedin a recess of the cylinder y2v so as to. be displaceable .in the axial direction of kthe lock casingthree of. the said engaging portions of the slide I0 being formed by recesses and the other two by a front and a rear oblique face of the slide respectively, that is, oblique engaging faces provided on the slide for cooperation with mating oblique faces on the sections 5 of the pin-tumblers 4, 5.

As the control key l is inserted in the plug 3 in the required manner, the pin-tumblers 4, 5 are successively forced out of the range of the keyhole 6. By cooperation of the front oblique engaging portion of the key shank with the section 4 of the rearmost pin-tumbler 4, 5 the slide l0 is positively shifted to the right from its position shown in Fig. 1 by cooperation of the section 5.0i said pin with the rearmost engaging portion 9 of the slide I0. By this means the remaining engaging portions 9 of the slide I 0 are caused to cooperate with the section 5 of the other four pin-tumblers 4, 5 so that these are positively adjusted.

Said cooperation ofthe key 'l with the sections 4 and that of the sections 5 with the slide l0 have the result that the joint between the two pin sections 4, 5 is positively moved into alignment with the periphery of the plug 3 as shown in Fig.

3. The locking action of the pin-tumblers 4, 5 is then terminated in consequence whereof the plug 3 is released so that it can be turned by means of the key. This rotational movement of the plug 3 is then transmitted to the locking bar of the lock (not shown) connected with this plug.

If in the condition of the lock as shown in Fig. 3 the key is pulled out of the plug 3, the sections 4 are forced outwardly, that is, out of the engaging portions of the key with the exception of the rearmost section, whereby the slide I0 is pos'i tively displaced to the left in regard to Fig. 3 into its position shown in Fig. 1. By this means the slide .I 0 positively pushes the rearmost portion 4 by means of the section 5 correlated to the latter inwardly into locking position. The other pin tumblers had thus entered into a locking position also due to having been moved in the outward direction and if, as illustrated in the drawing, provision is made for the pin-tumblers 4,15 to move in a vertical path, in consequence whereof, they have the tendency to drop by influence of theirv own weight into their lowermost position shown in Fig. 1 as the key is retracted, these tumblers freely move into a diiferent position of locking by locking engagement of their sections 5.l I

`If a keynot being coniigurated in accordance with 'the permutation chosen is inserted in the keyhole 6 there is absolutely no possibility of displacing the slide l0 for releasing theplug 3. From the foregoing explanations it will be clear without anyifurther comment that only a keyof a form according to the permutation chosen can be inserted in the lock to the depth required for rotating the plug 3 (after unlocking of the same).

According to one well known arrangement of .the Irow of pin-tumblers as illustrated in the drawing the keyhole is arranged as in the usual actual practice in the rotatable cylinder as a rule tionof the row of pin-tumblers in the lock casl ing may be horizontal instead of vertical when `the cylinder is locked. Further the lock may be provided with several rows of pin-tumblers instead'of with a single row, to which rows withthe tumblers distributed thereto in accordance with l,

the permutation chosen the key must naturally -be fitted. Again the shank of the key need not be flat. The conguration of the key in accordance with the permutation chosen may be effected by means of milled teeth instead of bored recesses; which former arrangement may include one or more rows to conform to the number of rows of pin-tumblers provided.

I claim:

In a pin-tumbler lock, a casing, a cylinder having a cylindrical bore and a longitudinal slideway. formed therein, a plug in the bore, a slide in said slidevvay, a keyway in said plug, a plurality of transverse bores in the plug and cylinder exr tendingfrom the keyway to the slideway, twopart pin-tumblers in said bores having their lines of junction iiush with the surface of the plug when the plug is to be turned in the cylinder, the slide being formed with a plurality of inclined surfaces each adapted to contact one of the tumblers, and a key formed with a plurality of spaced conical recesses in positions corresponding to the tumblers, the inner end of said key having an inclined surface and adapted to engage the innermost tumbler, each of said tumblers having conical outer ends, said slide being formed with an inclined surface adjacent the innermost tumbler adapted to be engaged by the adjacent conical end of the innermost tumbler and to be moved longitudinally thereby, the inclination of the last mentioned .inclined surface being opposite to that of the other inclined surfaces, said slide having a series of recesses registering with the adjacent ends of the respective tumblers except said innermost tumbler, said'recesses being adapted to accommodate the ends of the respective tumblers when the slide is in locked position and also when the slide is in unlockedposition and the respective tumblers are seated in the corresponding recesses of a properly formed key,said tumblers, when an improper key is inserted, being either positioned too high so as to prematurely contact the corresponding'inclined surface of the v slide and prevent longitudinal movement of the slide, thus preventingA the innermost tumbler fromv having the junction of its parts brought flush with the surface of the plug, or remaining itself too low with its junction of parts o ut of flush with said surface and preventing turning of the plug.

FRITZ SCHORI. 

